No

Antitubercular Agent

Treatment of tuberculosis and other mycobacterial diseases, in conjunction with other antituberculosis agents, when first-line agents have failed or resistance has been demonstrated

C

Contraindicated in patients with severe hepatic impairment or in patients who are sensitive to the drug

Use with caution in patients receiving cycloserine or isoniazid, in diabetics

>10%: Gastrointestinal: Anorexia, nausea, vomiting

1% to 10%:

Cardiovascular: Postural hypotension

Central nervous system: Psychiatric disturbances, drowsiness

Gastrointestinal: Metallic taste, diarrhea

Hepatic: Hepatitis (5%), jaundice

Neuromuscular & skeletal: Weakness

<1%: Dizziness, seizures, headache, peripheral neuritis, rash, alopecia, hypothyroidism or goiter, hypoglycemia, gynecomastia, stomatitis, abdominal pain, thrombocytopenia, optic neuritis, blurred vision, olfactory disturbances

Symptoms of overdose include peripheral neuropathy, anorexia, joint pain

Following GI decontamination, treatment is supportive; pyridoxine may be given to prevent peripheral neuropathy

Cycloserine and isoniazid; increased hepatotoxicity with rifampin

Inhibits peptide synthesis

Absorption: Rapid from GI tract (~80%)

Distribution: Crosses the placenta

Protein binding: 10%

Bioavailability: 80%

Half-life: 2-3 hours

Time to peak serum concentration: Oral: Within 3 hours

Elimination: As metabolites (active and inactive) and parent drug in urine

Oral:

Adults: 500-1000 mg/day in 1-3 divided doses

Dosing adjustment in renal impairment: Cl_cr <50 mL/minute: Administer 50% of dose

Prescriber may recommend an increase in dietary intake of pyridoxine to prevent neurotoxic effects of ethionamide.

Initial and periodic serum ALT and AST

May cause drowsiness or dizziness; case reports of depression and psychosis

None reported

No information available to require special precautions

No effects or complications reported

Take this medication as prescribed; avoid missing doses and do not discontinue without contacting prescriber. You will need to schedule regular medical checkups which will include blood tests. You may experience GI upset (small frequent meals may help), metallic taste and increased salivation (lozenges, frequent mouth care), dizziness, blurred vision (use caution when driving or engaging in tasks that require alertness until response to drug is known), postural hypotension (change position slowly), impotence and/or menstrual difficulties (these will go away when drug is discontinued). Report acute unresolved GI upset, changes in vision, numbness or pain in extremities, or unusual bleeding or bruising. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to be pregnant. Consult prescriber if breast-feeding.

Neurotoxic effects may be relieved by the administration of pyridoxine

Monitor initial and periodic serum ALT and AST

Tablet, sugar coated: 250 mg

Davidson PT and Le HQ, "Drug Treatment of Tuberculosis - 1992," Drugs, 1992, 43(5):651-73.

Donald PR and Seifart HI,"Cerebrospinal Fluid Concentrations of Ethionamide in Children With Tuberculous Meningitis," J Pediatr, 1989, 115(3):483-6.

"Drugs for Tuberculosis," Med Lett Drugs Ther, 1993, 35(908):99-101.

Iseman MD, "Treatment of Multidrug-Resistant Tuberculosis," N Engl J Med, 1993, 329(11):784-91.

Pattyn SR, Janssens L, Bourland J, et al, "Hepatotoxicity of the Combination of Rifampin-Ethionamide in the Treatment of Multibacillary Leprosy," Int J Lepr Other Mycobact Dis, 1984, 52(1):1-6.

Starke JR and Correa AG, "Management of Mycobacterial Infection and Disease in Children," Pediatr Infect Dis J, 1995, 14(6):455-69.